Abstract: The design flow management problem is a new research subject in CAD framework.This paper shows a group of basic concepts relevant to the design flow and implements the knowledge representation of the design flow with structure constraints and data constraints.Around the acquisition of design experience.the generation of complete knowledge,the execution of design flow,the handling of consistent problem and the evaluation of design.the paper discusses the knowledge-basad design flow management in CAD framework.Moreover,it presents the architectural design of a corresponding design flow management system.